Wire Type Research Articles

RESEARCH STATUS AND PROSPECTS FOR TIG-MIG HYBRID-ARC-WELDING TECHNOLOGY

TIG-MIG hybrid welding integrates the merits of tungsten insert-gas welding (TIG) and metal inert-gas welding (MIG), and achieves a new material-joining process with high quality, high efficiency and low cost. However, TIG-MIG hybrid welding also had some shortcomings, such as a complex process, unstable arc, large heat input, limiting its application. To further improve and promote TIG-MIG hybrid welding, numerous universities and research institutes have put forward a series of improvement programs that achieve relatively good results. In this study TIG-MIG hybrid welding is discussed in three aspects: the welding-process improvement, welding-parameters optimization and numerical simulation of the welding process. It was found that the stability of the hybrid arc welding process and the quality of the weld bead can be improved by improving the current polarity, wire type and arc swing. The TIG current, the distance between the wire and tungsten, and the heat input had an important impact on the weld quality and the formation of defects. A numerical simulation of the welding process analyzed the effects of torch angle, the distance between the wire and tungsten, the welding speed and the temperature fields on the arc morphology, molten-pool behavior, and droplet transfer. According to the above analysis, it summarized the current research status of TIG-MIG hybrid welding, and then proposed future research directions based on the existing shortcomings and deficiencies.

Cotton fiber-based 1D nanocomposite: a new type of flexible wire for cryogenic electrical system

Cotton fiber-based 1D nanocomposite: a new type of flexible wire for cryogenic electrical system

Bioabsorbable Composite Laminates of Poly‐Lactic Acid Reinforced with Surface‐Modified Mg Wires for Orthopedic Implant Applications

Unidirectional and multidirectional laminates of Mg‐wire‐reinforced poly‐lactic‐acid–matrix composites are manufactured by an improved compression molding strategy that allows excellent control on the position and orientation of the wires. Two different types of Mg wires, with and without surface modification by continuous plasma electrolytic oxidation, are used, the former to improve the interfacial strength and to reduce the degradation rate of Mg wires in biological environments. The mechanical properties of the constituents as well as of composites are measured before and after in vitro degradation by immersion in simulated body fluids and the corresponding deformation, fracture, and degradation mechanisms are analyzed in detail. It is found that the presence of the Mg wires improves the mechanical behavior in tension and compression of unidirectional composites in the longitudinal direction (close to cortical bone) and that quasi‐isotropic laminates with tailored properties can be designed from the data of unidirectional composites.

Heating of metallic orthodontic devices during anti-aging treatment with vacuum and electromagnetic fields: In vitro study.

The physical appearance of an individual plays a primary role as it influences the opinion of the viewer. For this reason, orthodontic therapy to improve perceived aesthetics is in high demand among patients. This factor, combined with the increase in the number of non-invasive facial aesthetic treatments, has led to the need to understand potential risk factors in the application of medical devices to the perioral skin in patients with fixed orthodontic appliances. The aim of this study was to evaluate in vitro heating of the orthodontic bracket following electromagnetic fields and negative pressure (V-EMF) used as an anti-aging treatment. Two different types of titanium alloy wires, one made of "beta-Titanium" alloy and the other "Ni-Ti" (DW Lingual Systems GmbH-Bad Essen-Germany) were used. The orthodontic wires and brackets mounted on a resin mouth were covered with porcine muscle tissue, then subjected to anti-aging therapy with a Bi-one LifeTouchTherapy medical device (Expo Italia Srl-Florence-Italy) which generates a combination of vacuum and electromagnetic fields (V-EMF) already adopted for antiaging therapy. During administration of the therapy, the orthodontic brackets and porcine tissue were thermally monitored using a Wavetek Materman TMD90 thermal probe (Willtek Communications GmbH-Germany). In total 20 orthodontic mouths were used, 10 with Beta Titanium wires and 10 with Nickel Titanium wires. A temperature increase of about 1°C was recorded in each group. The outcome of the present research shows that the absolute temperatures measured on orthodontic appliances, which, despite having a slightly different curve, both show an increase in temperature of 1.1°C at the end of the session, thus falling well within the safety range of 2°C as specified by the standard CENELEC EN 45502-1. Therefore, V-EMF therapy can be considered safe for the entire dental system and for metal prostheses, which tend to heat up at most as much as biological tissue (+0.9°C/1.1°C vs. 1.1°C/1.1°C). In conclusion, anti-aging therapy with V-EMF causes a thermal increase on orthodontic brackets that is not harmful to pulp health.

The driving characteristics of bidirectional SMA wire actuators - Theoretical modeling and experimental testing

Bidirectional shape memory alloy (SMA) wire actuators play a critical role in driving applications thanks to their characteristics in memory shaping and good overall performance. SMA wire actuators were often studied at a single load type, and there is no comprehensive comparison investigation of different SMA wire actuators in the literature. In this paper, the driving characteristics of four available types of SMA wire actuators, namely, dead-load, biased spring, differential type, and biased superelastic SMA wire actuators are modelled mathematically and then tested in laboratory settings. The characteristics of SMA wire actuators are quantitatively measured and then compared under a range of application scenarios. The output displacement and thermal-electric models of NiTi SMA wires are derived based on the Brinson constitutive model with stress effects in consideration. A customized SMA wire actuator test device is developed to evaluate the theocratical models and benchmark testing four types of SMA wires and their driving characteristics, including structure, design, displacement, response and recovery time, energy efficiency and hysteresis properties. The SMA wire phase transformation characteristics of the four actuators are tested under different activation currents, and then quantitatively compared. In conclusion, this paper adds theoretical and experimental significance to the literature on SMA wire actuators. The reference value on the phase transformation characteristics of SMA wires can be used to guide SMA application in industrial designs and enable theoretical studies in complementary research areas.

Effect of Elastomeric Module Degradation and Ligation Methods on Kinetic Friction between NiTi or Stainless Steel Wires and Stainless Steel Brackets.

Objectives: The reduction of resistance to sliding between the archwire and bracket promotes more seamless tooth movement, leading to a faster and improved orthodontic treatment experience. This research aimed to examine how the degradation of elastomeric modules, different ligation methods, bracket-wire angle, and wire type (nickel titanium, NiTi or stainless-steel, SS) impact the kinetic friction resulting from the interaction between NiTi or SS archwires and SS brackets. Materials and Methods: The current in vitro study was conducted on nine groups, including NiTi and SS archwires with three types of ligations (O-ring, figure of 8, and SS wire ligature) and two bracket-wire angles (0˚ and 10˚). The kinetic friction in each group was measured using a Universal Testing Machine at four time intervals: baseline, day one, week one, and week four. Repeated measures ANOVA, Mauchly test of sphericity followed by the Greenhouse-Geisser test, and relevant post hoc tests were used for statistical analysis (P<0.05). Results: The authors found a decrease in kinetic friction in all types of ligations, which confirmed the effect of time on the degradation of ligation modules. The kinetic friction of figure of 8 ligations was higher than both O-ring and SS wire ligations. No difference was observed between O-ring and SS wire ligations. Furthermore, the bracket-wire angle did not affect friction. Conclusion: The authors suggest that the use of figure of 8 ligations in NiTi and SS wires should be limited due to their high friction and replaced with other types of ligations, if possible.

Refined risk assessment and differentiated protection of lightning damage in distribution network lines considering the underlying surface environment

The distribution line is widely distributed and the span of pole-towers is small. However, the existing lightning positioning system has limited positioning accuracy, and the lightning strike coordinates it locates have certain deviations for the distribution network. The lightning hazard risk divided by lightning density is not sufficient to support the differentiated lightning protection transformation of the distribution network. The environment of the underlying surface where the pole-tower is located has a significant impact on lightning activity, so this paper combines terrain, climate, lightning current characteristics, and historical lightning trip data to finely evaluate the lightning risk level in the distribution line pole-tower area. This paper provides a detailed analysis of the relationship between different underlying surface environments and lightning current characteristics and utilizes the entropy weight method to construct a comprehensive lightning disaster risk index, then evaluates the risk level of lightning disaster in different regions, and corrects it through lightning fault data. Overlaying the risk level of the area and the distribution map of the pole-tower foundation coordinates, it will obtain the distribution of lightning hazard-pregnant risk at the pole-tower area, which would contribute to guiding the differentiated lightning protection transformation of the line. Compared to traditional unified lightning protection renovation methods, differentiated lightning protection methods that integrate factors such as pole-tower structure, wire type, and lightning risk level can achieve significant lightning protection effects at a lower economic cost. Taking Nanchang City as an example, risk assessment and lightning protection renovation were conducted on 21 distribution lines. The average number of lightning trips per year is 55 before the renovation, but it is only 4 after the renovation, which the number of lightning trips significantly reduce. This verifies the effectiveness of using lightning hazard-pregnant assessment results to guide differentiated lightning protection methods.

Silver Bonding Wire - an Alternative for Mechanical Sensitive Chip Configurations in Automotive Electronics Packaging

Silver (Ag) bond wires are mainly used in consumer products as a reliable low-cost alternative to gold (Au) bond wires. In previous investigations, we have shown that silver wires also have potential for use in the automotive sector (1, 2, 3, 4], where the materials are exposed to particularly harsh environmental conditions. In order to understand thc intluence of these conditions in the electronic package on the silver-aluminum material system, we carried out extensive studies on test packages built on laboratory level. For the future development of challenging automotive devices, it will be important to have a cooperation between semiconductor package developer and material supplier with an assist of characterization spccialists. In this project, we formed a threeparty project in which characterization specialists, package developer, and wire manufacturer collectivcly conduct a feasibility study of a new Ag wire material for automotive application. Two wire types (standard Ag wire and new type of Ag wire GX2s) were chosen for the investigation in direct comparison regarding long-term reliability. Samples were built under mass production conditions and then subjected to various reliability tests following AEC-Q006 requirements. Subsequently, mechanical characterizations by means of ball shear and pull tests as weil as high resolution SEM microstructure analyses on cross-section samples are applied. In the paper, results of the different tests will be summarized, but a more in-depth analysis will be given to the temperature cycle test (TCT), where the most significant differences between the sample variations occurred. Overall, the results show the importance of the knowledge for the material reliability upfront a device qualification process (robustness validation) and give further guidance for material selection.

PLIF Flame Study on the Qualitative and Quantitative Measurement of OH Species for Conventional and Alternative Jet Fuels; Experimental and Theoretical Investigations

ABSTRACT The hydroxyl molecule is one of the most important intermediate species in the chemistry of combustion processes and plays an important role in the chemical reactions of a hydrocarbon-air flame. However, investigation on a laser-based quantitative measurement of OH in heavy liquid hydrocarbon flames remains very scarce. Thus, in this study, OH radicals were measured qualitatively with the aid of planar laser-induced fluorescence in atmospheric pressure studies of burner stabilized laminar flames of kerosene and alcohol-to-jet (ATJ) fuel. These qualitative profiles were then put on a quantitative basis by analysis of the impact of temperature on the Boltzmann distribution of OH over the ground electronic state rotational energy levels and the use of a simple methane reference flame and its modeling using ANSYS Chemkin-Pro. The quantitative profiles in turn were used to validate the developed chemical kinetic mechanisms of kerosene and ATJ combustion. An experimental apparatus has been developed to investigate the temperature profile and the OH relative amounts of kerosene and ATJ laminar flames in an optimized premixed flat flame burner, under three different air/fuel ratio conditions. Fine wire type thermocouples were applied to provide reliable temperature profiles for the fuel flames. In general, reasonable agreement were observed between the experimental OH results and the simulations for the target fuel flames in the case of kerosene, while a higher peak value of OH was predicted in the ATJ model output compared to the PLIF derived data.

Additively-manufactured Mg wire-reinforced PLDL-matrix composites for biomedical applications

Coupons of a medical grade PLDL polymer matrix uniaxially reinforced with a 15% volume fraction of Mg wires have been manufactured by fused filament fabrication for the first time. Two different types of Mg wires, without and with a surface treatment by plasma electrolytic oxidation were used. Both composite materials were subjected to degradation in phosphate buffer solution over a 3-week period, and their degradation and deformation micromechanisms were analysed in detail. Additionally, the materials were subjected to extensive mechanical testing under various loading conditions, and the interface strength was also analysed. It was found that the presence of the Mg wires improves the mechanical behaviour and accelerates the corrosion rate of the composite with respect that of the polymer matrix and these properties can be further tailored through the surface-modification of Mg wires by plasma electrolytic oxidation. The additive manufacturing strategy presented opens the path to fabricate multimaterial implants and scaffolds with complex shape and tailored properties provided by biodegradable polymers reinforced with either Mg and Zn particles and/or wires.

Derivation of Ambient Enhancement Factors of Impregnated Twisted Pairs for Partial Discharge Risk Evaluation

Partial discharge (PD) is the main issue challenging the electrical machine (EM) insulation system for more electric aircraft (MEA) applications. Indeed, the trend of adopting higher DC link voltage and fast switching device further boost the risk of PD. Partial discharge inception voltage (PDIV) is mostly dominated by ambient conditions (i.e., temperature, pressure, and humidity), and their influence is accounted for through experimentally determined ambient enhancement factors. For non-impregnated windings, ambient enhancement factors are suggested by both IEC 60034-18-41 and recent literature. However, in many applications, EMs’ windings are often impregnated with resin to improve thermal performance, mechanical resistance, and electrical insulation. In this case, no indications of the enhancement factors for PD risk assessment are given. The ambient enhancement factors are experimentally determined in this paper to enable the PD risk evaluation for impregnated windings. These factors are obtained relying on an extensive PD investigation, where PDIV and partial discharge extinction voltage are measured under variable temperature, pressure, and humidity conditions. Finally, the tests are performed on different wire types and motorette samples to validate the applicability of the derived factors.

Failure Analysis on OPGW Cable During Short Circuit Test

A new type of ground wire used for communication lines in high-voltage power transmission systems is called Optical Ground Wire cable (OPGW). In addition to serving as a communication optical cable and standard overhead ground wire, it may also prevent lightning strikes and carry short circuit currents. The OPGW cable must fulfil the specifications for both construction and performance for the ground wire to work, the optical fiber integrity, and the optical transmission characteristics to be appropriate for the intended use. It is anticipated that OPGW cables will safeguard the optical fiber and that the cable’s temperature won’t rise to the point where the fiber’s parameters could deteriorate. This paper examines the analysis and review of OPGW cable failure cases during short circuit tests.

Initial arch wires used in orthodontic treatment with fixed appliances.

Initial arch wires used in orthodontic treatment with fixed appliances.

Experimental study of a temperature measurement system for an overhead power line using sensors based on TFBG

This article presents the use of an inclined fiber sensor Bragg grid to control the extension of wires in overhead lines. An aspect of the technological novelty of the project is the development of an innovative optoelectronic system for monitoring and diagnosing the condition of building structures based on a combination of conventional Bragg gratings. The lighting power sensor is installed directly on the controlled transmission of the power line in the form of fittings with a copper plate. A photosensitive multimode optical fiber is attached to the copper plate, at the end of which an inclined fiber Bragg grating is fixed, connected to a multimode optical fiber using a fiber-optic connector through an optical connector. An ultraviolet excimer laser and a light power detector are connected to a fiber-optic connector. The study showed that by selecting the appropriate mechanical parameters of the extension transformer, taking into account the optical parameters of the sensor, and using a special filter, the optical-mechanical system can be configured in the required range to control the sagging of the overhead line wire. During measurements to simulate the operation of a power line wire, the temperature was forced to vary in the range of 10-60°C. This led to the lengthening of the test wire from 38.987 m to 49.275 m; the error was within 4%. The deflection range depends on the distance between the supports, the type of wire, and its actual length in the span, which actually determines the deflection.

To Evaluate the Effect of Prophylactic Agents on the Surface Morphology of Different Orthodontic Wires at Different Temperatures: An In vitro Study

Aim and Objective: The aim and objective are to evaluate the effect of prophylactic agents on the surface morphology of different types of orthodontic wires of different dimensions at two different temperatures. Materials and Methods: Stainless steel (SS), NiTi, and titanium-molybdenum alloy (TMA) wires of 0.016 inch round and 0.017 inch × 0.025-inch dimensions were immersed in prophylactic agents such as 0.2% NaF, 0.2% CHx and 1.23% APF for 1.5 h at 37°C and 45°C. A one-way analysis of variance, Bonferroni test, and intraclass correlation coefficient test was performed to eliminate the bias. Scanning electron microscope was used to evaluate the surface characteristics of wire and quantitative analysis was performed using ImageJ software. Results: Highest corrosion can be seen on TMA wires of 0.016 inch and 0.017 inch × 0.025 inch when exposed to 1.23% APF gel at 45°C and lowest corrosion can be seen on SS wires of 0.017 inch × 0.025 inch when exposed to 0.2% NaF mouthwash at 37°C. Conclusion: The results suggest that sodium fluoride is the mouthwash of choice when used with all three types of orthodontic wires used for different orthodontic purposes and APF gel should not be recommended when TMA wires are used at high temperatures as it causes corrosion which can lead to increased friction.

АНАЛИЗ КОНФИГУРАЦИИ СЕЛЬСКИХ ЭЛЕКТРИЧЕСКИХ СЕТЕЙ 10 КВ

Currently, the works of domestic and foreign scientists explore options for improving medium-voltage electrical grids by introducing distributed automation tools. However, statistical data on the configuration of existing rural power grids of 10 kilovolts are not sufficiently presented in the literature. (Research Purpose) The research purpose is analyzing the configuration of rural electrical grids of 10 kilovolts, taking into account the transformer substations connected to them and the types of wires used. (Materials and methods) The analysis of 165 supporting schemes of 10 kilovolt overhead power transmission lines of one of the electric grid companies was carried out. (Results and discussion) It is found out that the arithmetic mean of the length of the overhead line of 10 kilovolts to the most remote point of the grid is 9.2 kilometers, and the total length is 13.2 kilometers. It is found that that the specific power per kilometer of the rural grid of 10 kilovolts is 82 kilovolt amperes per kilometer. At the same time, an average of 5 taps are from one 10-kilovolt line, and the average length of the them is 0.68 kilometers. It was also revealed that 72 percent of the total length of the analyzed power transmission lines of 10 kilovolts does not meet the requirements for mechanical strength under icy and wind loads. (Conclusions) The analysis reflects the current configuration of rural 10 kV power grids in the Orel region, while 10 kV overhead lines in other regions may have their own characteristics.

Optimization of losses by switching to higher voltage in distribution networks

The article considers the basis of scientific research in the field of electric power industry the issues of transition to 20 kV voltage in the distribution power grids of Uzbekistan. The main advantages of this method are analysed, as well as the factors affecting power and energy losses in electrical systems and networks. The paper presents a schematic diagram of an electric network section, on which a comparative calculation and analysis of voltage, energy and power losses in 6/10/20 kV networks is carried out. Special attention is paid to the peculiarities of calculation of these parameters, as well as the basic expressions for their calculation and the resulting graphical relationships. From the analysis it can be concluded that it is reasonable to use 20 kV voltage in distribution networks. It allows to reduce power and energy losses, which is an important factor in the efficient operation of electric power systems, to increase line capacity and service range. However, when selecting the optimal voltage for certain conditions, it is necessary to take into account a number of factors, such as the length of transmission lines, the type of wires and transformers used, and the load level of the network.

Developing adjustable stiffness for smart material of magnetorheological elastomer to diminish vibration

Many vibration isolators, such as passive vehicle mounting devices, have an inflexible stiffness. This article presents the development of a smart material vibration isolator based on magnetorheological elastomer (MRE), which has adjustable stiffness to minimize unwanted vibrations. The objective of this research is to first create a design for the vibration isolator, and then simulate a magnetic circuit. The Finite Element Method Magnetics (FEMM) software was employed to simulate the effectiveness of the electromagnetic circuit in generating a magnetic field through the vibration isolator by employing MRE samples. Pure iron was chosen as the material for the housing of the vibration isolator test rig. To attain an optimal magnetic field, an inventive design of the magnetic circuit, including examination of the wire type, size, and coil turn number, along with the housing material of the test rig, was performed. The study analyzed the performance of the MRE vibration isolator concerning different current inputs in the coil. The results indicate that the stiffness value of the MRE-based isolator system can be more effectively modified by increasing the current inputs. Therefore, a larger current input leads to a greater change in stiffness.

Comparative Evaluation of Durability and Hygiene Between Multistrand Round Dead Soft and 8-Braid Flat Dead Soft Stainless Steel Retainer Wire

Aim and Objectives The present study aims at evaluation and comparison of durability and hygiene between 2 different lingual retainer wires bonded between premolar to premolar, that is, maxillary or mandibular arch in the same patient. Materials and Methods Eighty retainer wires were placed in 40 patients. They were assigned to 2 groups and subjected to 2 different types of retainer wires (multistrand round and 8-braid flat). Results The mean durability of multistrand round retainer wire (235.7 ± 67.28 days) was more than 8-braid flat retainer wire (153.5 ± 43.85 days) irrespective of arches to which they were bonded, which was statistically significant. Scores for plaque index, calculus index, and gingival index were found more with 8-braid flat retainers and in lower arch than multistrand round retainer and in upper arch but these are statistically not significant. Conclusion The mean durability of multistrand round retainer wire was more than 8-braid flat retainer wire. The analysis did not find any statistical significant association for deposition of plaque, calculus, and gingival inflammation between different retainer wires and between arches.

Pulse power plasma stimulation: A technique for waterless fracturing, enhancing the near wellbore permeability, and increasing the EUR of unconventional reservoirs

The inherent characteristic of unconventional and ultra-low permeability reservoirs is a small drainage area that negatively affects the production rate and ultimate recovery (UR). Drilling horizontal wells, coupled with a stimulation process such as hydraulic fracturing, are applied to wells in these reservoirs to enhance well productivity. Although hydraulic fracturing has been the most famous stimulation technique in these reservoirs and has contributed to the increased US oil and gas production during the last several years, other stimulation techniques may be competitive with (or complementary to) hydraulic fracturing. This is because the main contribution to production in these reservoirs would be from complex fracture networks (often micro-cracks) combined with enhanced formation permeability rather than the classical two-wing fractures. Hence, a near-wellbore stimulation technique for improving the permeability of these reservoirs by activating the existing natural fractures and creating secondary microfractures would be highly desired. This paper investigates the pulse plasma stimulation technique to investigate such an approach of waterless stimulation/fracturing that creates multiple fractures and is also a permeability enhancement method. In this method, plasma is generated by discharging a high voltage and high current electrical energy in a very short time into two electrodes submerged in a wellbore filled with aqueous fluid. This study is divided into two sections. The first part presents experimental and numerical examples of stimulation/fracturing induced by pulse plasma in different rocks. Several parameters, including the effect of discharge with and without wire, input energy, confining stress, and rock type, on the induced fractures are studied. The second part uses the insights and results from the first part to numerically investigate pulse plasma's effects on production. Measurement of the formation permeability around the generated fractures indicated that the shock wave generated multiple fractures and increased the rock permeability by more than one or two orders of magnitude. The second part of the numerical section discusses the increased estimated rate and ultimate recovery (EUR) of horizontal wellbores due to fracturing and modified permeability resulting from pulse plasma. We present a sensitivity analysis on the magnitude and extent of the improved permeability region and its impact on EUR.